Enzymatic synthesis of octyl glucoside catalyzed by almond β-glucosidase in organic media

Abstract

The synthesis of n-octyl-β-D-glucopyranoside can be performed by direct condensation of 1-octanol and glucose, catalyzed by immobilized almond beta-glucosidase, using solid glucose suspended in 1-octanol as a reaction media. Both the rate of reaction and the conversion could be enhanced by using acetonitrile and N,N-dimethylformamide (DMF) as co-solvents, the latter giving the best results. The rate of reaction was dependent on the concentration of DMF and on the initial water activity (aw), with higher water activity fostering faster reactions. The rate increased with DMF concentration, up to 20% DMF, but diminished rapidly at higher concentrations. Product concentration could be increased from 40 to 100 mM by going from 0 to 20% DMF; however, it was not sensitive to the initial water activity.Key words: β-glucosidase, alkyl glycosides, reverse hydrolysis, water activity, organic solvent.